Tobque conveying and converting -apparatus



1943- R. B. ASPINWALL ET AL Re. 22,

TORQUE CONVEYING AND CONVERTING APPARATUS 8 Sheets-Sheet 1 Original Filed Dec. 10, 1934 INVENTORS 57 031 13. j'yler J-n'fillbfiffl fispz'nwall Feb. 16, 1943- R. B. ASPINWALL ETAL 22,267

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. INVENTORS 5/746? :5. filer JQoberf 2?. J1 62mg 7e Feb. 16, 1943- R, B. ASPINWALL ET AL Re. 22,267

TORQUE CONVEYING AND CONVERTING AFPARATUS Original Filed Dec. 10, 1934 8 SheetsSheet 5 INVENTORJ fi filer ATI' RNEYS.

Feb. 16, 1943. R, a. ASPINWALL ET AL Re. 22,267

TORQUE CONVEYING AND CONVERTING APPARATUS Original Filed Dec. 10, 1954 8 Sheets-Sheet 6 AT ORNEYS Feb. 16, 1943. B ASPlNWALL ETAL Re. 22,267

TORQUE CONVEYING AND CONVERTING APPARATUS 1954 8 Sheets-Sheet 7 Original Filed Dec. 10

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TORQUE CONVEYING AND CONVERTING APPARATUS Original Filed D90. 10. 1934 8.Shee1;s-Sheet 8 INVENTORS TRACY B.TYLER B RQBE BASPI WALL Reissued Feb. 16, 1943 TORQUE CONVEYING AND CONVERTING APPARATUS Robert B. Aspinwall. Hazel Park, Mich, and Tracy B. Tyler, Miami Beach, Fla, assignors to The Monopower Corporation, Detroit, Mich, a

corporation of Michigan .OI'ig'inaI No. 2,183,761, dated December 19, 1939,

Serial No. 756,900

, December 10, 1934.

Application for reissue December 19, 1940, Serial No.

This invention relates to coupling and torque conveying and converting apparatus, particularly to clutching means and to mechanisms of the class commonly termed "speed change transmissio Broadly stated, the invention aims to provide, in conjunction with such devices,-improved automatic controlling means for changing the torque and speed converting ratio automatically and in response to relative speed and/or torque demands upon a source of power, and, generally, to overcome numerous disadvantages inherent in automatic clutches and transmissions as they have heretofore been designed and constructed, as well as to incorporate therein a number of improvements conducive to smooth and fool-proof operation, strength, simplicity and in-- vision of such an automatic automotive transmission which provides for' an uninterrupted flow of power from the engine to the rear wheels while ratio changing is in progress, eliminating all hesitation and loss of power, speed and time, and waste of fuel, such as are caused by shifting when conventional transmissions are used wherein it is necessary to interrupt the power flow while changing from one torque ratio to another. An incidental object flowing from that last mentioned is the provision of a transmission enabling 33 Claims. (Cl. lb-336.5)

shifting means, with or without interruption of power flow, yet clashing, noise or jerks in shifting or injury to working parts through unskilli'ul operation of such controlling means is impossible.

This invention also aims to improve upon the automatic transmission construction disclosed in the copending application 10! Robert B. Aspinwall, Serial No; 706,232, filed January 11, 1934,

to eliminate the necessity of providing a separate main clutch, and to incorporate improved automatic clutching means and personally controllable shifting means, as well as to improve said transmission in other respects which will become apparent as the description proceeds.

Still another object is to incorporate in a compact unitary assembly improved wet and dry clutches, and centrifugal and power-operated clutches, arranged to act cooperatively and assembled in one unit, yet in which the wet and dry clutches are completely isolated from one another and leakage of liquid into the latter is faster acceleration of a vehicle, by completely eliminating the unavoidable deceleration which occurs when it is necessary to disconnect the drive as when shifting in the ordinary manner.

Still another-object is the provision of such an automatic transmission in which shifting may be effected smoothly and silently regardless of the speed of the vehicle and the skill of the driver. I

A still further object is the provis v of improved means, directly controllable by he operstar of a vehicle equipped with a transmission constructed in accordance with our invention, whereby the speed or torque ratios may be directly controlled independently of the automatic I impossible.

Another object oi the invention is to provide in such mechanism novel means for eflectively reducing heat generation and for rapidly dissipating such heat as is unavoidably produced.

Another object is a means for automatically effecting a driving connection between any power generator and mechanism to be driven thereby, where high torque conditions are necessary before direct drive conditions are established, as for example the driving of machines from electric motors not provided with special windings or other accessories,

Other objects include the provision of improved liquid sealing and conducting means, improved fluid pumping and controlling mechanism, a novel manner of floating certain of said pumping and controlling apparatus upon a rotating shaft within the transmission casing, and of manifolding certain of the fluid channels, novel and extremely compact centrifugal governing means, an improved fluid regulating system responsive to such centrifugal governing means, and simple and positive means for destroying eflectiveness of the fluid controlling means during reverse operation of the transmission.

Other objects worthy of'specific mention are, to improve centrifugal clutch constructions, in respects not only eliminating "grabbing and chatter", but providing greater ruggedness and longer life, and which further maintain the dynamic balance of the rotating parts in a novel manner, and also to provide for uniform application, uniform increase of clutch pressure, and

a predetermined maximum clutch pressure, throughout the range of operationof the applyingmeans.

Other objects and advantages will be apparent from the following description, wherein refer-v ence is made to the accompanying drawings illus-- trating preferred embodiments of our invention,

and wherein similar reference, numerals designate similar parts throughout the several views.

In the drawings:

Figure 1 is an assembly view showing in side and sectional elevation and partly broken away an automatic transmission and clutches incorporating the principles of our invention and suitable ior use in automotive vehiclesas well as in other rotation conveying installations.

Figures 2a and 2b are enlarged substantially central vertical sectional elevations of diilerent portions of the device, one view forming a continuation of the other.

Figure 3-is a fragmentary side elevation of an oppomte side of the device from that shown in Figure 1, sectionally showing part of the automatic governing apparatus and a connected manually operable control assembly.

Figure 4 is a fragmentary cross section of a part of the centrifugal clutch operating means, taken substantially on the line 4-! of Figure 2a and looking in the direction of the arrows.

Figure 5 is a fragmentary section taken substantially on the line 5-4 of Figure 2a and looking in the direction of the arrows.

Figure 6 is a fragmentary edge view of certain of the clutch plates taken as indicated by the line 6-0 of Figure 5 and looking in the direction of the arrows.

Figure 'l is a fragmentary cross section of the hub portions of the wet clutches, taken substantially on the line 1-1 of Figure 2a and looking in the direction of the arrows.

Figure 8 is a vertical cross section taken substantially on the line 88 of Figure 2b and looking in the direction of the arrows.

Figure 8a is a sectional detail taken substantially on the line lia'la of Figure 8 and looking in the direction of the arrows.

Figure 8b is a sectional view taken substantially on the line elf-ab and looking in the direction of the arrows, the outer bells of the governor assembly being removed to show one of the fly-weights, and the spring means therefor, in plan.

Figure 9 is a vertical cross section taken substantially on the line 9-9 of Figure 2b and looking in the direction of the arrows.

Figure 10 is a vertical cross section taken substantially on the line lll||l of Figure 2b and looking in the direction of the arrows.

Figure 11 is a vertical cross section taken on the line ll-ll of Figure 2b and looking in the direction of the arrows.

Figures 12 and 13 are detailed sections taken substantially on the lines i2-i2 and li-II oi Figure 10 and looking in 'the direction of the arrows.

Figure 14 is a perspective of the governor controlled valve operating arm;

Figure 15 is a view similar to Figure 2c of a clutch assembly of somewhat modified construction.

Figure 16 is a fragmentary detailed sectional elevation of a somewhat modified unitarily slidable gear and overrunning clutch assembly and cooperatin parts.

is a fragmentary sectional detail It the ratio changing and control assembly.

taken on a plane corresponding to that of Figure 10 and showing somewhat modified actuating means for the automatic control valve.

Figure 18 is a sectional detail looking in the opposite direction, showing the construction of the valve actuating arm.

THE PRINCIPAL ELEMEN'IS 1N GErlEIiM.

Referring now to the drawings, it will be seen that our improved apparatus is formed in two coupled sections, each section being of unitary construction. ure 1, and in its entirety in Figure 2a, constitutes the clutching assembly, while the unit at the right in Figure l and most of which is shown in greater detail .1 Figure 2b, constitutes It will be understood that Figures 2a and 2b are to be read with the latter arranged as an aligned continuation at the right of the former, so that the parts occupy the relative positions in which they are shown in Figure 1.

Reference character I designates the driving shaft, to which is secured the flanged flywheel portion 2, which serves to partially house" the clutching means presently to be described. Carried by and cooperating with the cupped flywheel portion 2 is a belied casing portion 88 secured to the flywheel flange by cap screws II and forming with the flywheel a housing for main clutching means operable independently by either centrifugal force or fluid pressure means, to couple to the flywheel and driving means a driven drum 4 contained within portions 2-". In the construction illustrated in Figures 1 and 2a, clutch facingslil, 5B are shown arranged upon opposite faces of the drum. The centrifugal operating means for the main clutch is generally designated 3, while the fluid pressure operable applying means acts in chamber I12 to expand diaphragm I13,

Within drum 4 are a pair of wet clutches, the rearmost of which is generally designated 5 and constitutes the intermediate speed clutch, while the similar forward assembly, designated 8, constitutes the direct drive clutch. The construction and operation of these parts will presently be set forth in detail.

Similarly generally indicating the principal elements contained within the rear casing section I: a main gear set, 8-9, is provided (Figures 1 and 2a), an fiitermediate speed gear set l0-ll (Figures 1 and '2b), and a low speed gear set, "-13, within the latter of which gears is disposed an overrunning clutch IS. A centrifugal governor assembly generally designated I1, and a pump and valve assembly I8, are mounted on transmission shaft 56. Associated with and arranged exteriorly or the easing 1 are a manually or personally operable control assembly I! (Figure 10), a shifter control 20 (Figure' 3- -also manually operable) and a suction torque-responsive automatic control assembly 2|.

Gearing Considering now the outlined parts in greater detail, and particularly the torque converting gearing, it should be observed that the unit comprising gear it, its hub section 45, and the interposed overrunning clutch, is mounted for slidable movement upon its supporting driven sleeve 4?. The hub 45 which is splined upon the driven sleeve is drivable by the gear l3 through the interposed overrunning clutch IE, but the overrunning clutch prevents driving the gear That shown at the left in Fi8- shifting means just described by means of a Bowden wire and conduit assembly 24-25. This manual control instrument panel unit will be seen to comprise a suitable supporting bracket 4| and a plunger or rod 23 operable by means of a knob 22, the plunger being of course connected to the Bowden wire 24, and suitably notched as at 42 to define the neutral position of the gear, I3. Said gear is shown in such neutral position in Figure 2b, and it will be seen that when slid to the left as viewed in that figure it may be engaged with the gear I2 to establish a forward drive connection, while when slid to the right to engage gear I3 with a reverse idler I 5, a reverse drive connection is established. Movement of the gear I3 from one to another of these positions is manually efi'ected by means of the control knob 22, which, however, need not be manipulated at all in ordinary forward operation and starting and stopping of the driven mechanism.

Gear II is yleldably held in whichever of these three positions it may be located, by means of a spring-pressed detent 34 cooperating with pockets 35 in the slidable shifter rail 3 I.

The overrunning clutch within gear I3 comprises a plurality of rollers 44 housed in pockets formed by inclined flats (undesignated) on the periphery of hub 45. Although this overrunning clutch may be formed in any desired manner, it is preferably-constructed as disclosed in the copending application of Robert B. Aspinwall above referred to, the rollers 44 being caged in a bushing 43 slotted to receive them, while the bushing serves as a bearing for the annular gear portion I3 which also constitutes the driven clutch element. Torque is applied to the cage to urge the rollers toward wedged position by suitable torsion spring means (unshown) acting through a collar 48 provided with lugs 41 interfitting with the cage bushing 43, the collar and so the cage and roller assembly being retained in position by a snap ring 46. When the rollers 44 occupy the deepest portions of the flats, they do not project beyond the periphery of bushing 43, the outer gear assembly I3 being then simply journaled on the bushing, while when in wedging position the rollers are urged through the slots in the bushing and into engagement with the annular inner surface of the ring gear I3 to lock the same to the hub. The flats are so inclined that when gear I3 is driven by gear I2 to drive the vehicle or driven element in a forward direction, the clutch is thereby locked, but turning the driven shaft faster than gear I3 causes the clutch to overrun, as above indicated.

When the gear I3 is moved to the reverse (right hand) position, the overrunning clutch is rendered ineffective or inoperative by engagement of the clutch teeth 241-248, the former carried by element I3 and the latter by the driven sleeve 49.

while when gear I! is moved to the forward drive (left hand) position, the hub 45 and driven sleeve 49 are locked to the transmission shaft 56, by enlar is keyed to the transmission shaft 58 as at 55.

The rear extremity of the transmission shaft 56 will be seen to-be journaied in the driven sleeve 49, in which it is retained by pins, as 58, projecting through the sleeve and into rotatable engagement with a split collar 51 arranged in a perlph eral groove (undesignated) in the shaft, the pins being retained by a snap ring 59. Sleeve 49 is in turn journaled in the rear wall of housing I, as in the anti-friction bearing 50, and may carry at its rear extremity and outside the housing a driven coupling element 5|, to which, through suitable universal or other connections (unshown) the propeller shaft of a vehicle, or other element desired to be driven (also unshown) may be coupled.

The split collar 51 will be seen to take care of the thrust of helical gears without extra bearings by providing axial connection between shaft 56 and sleeve 49.

Low speed gear I2 and reverse gear I4 are rotatable as a unit and upon countershaft 8|, the gears being shown as formed integrally with a sleeve 19, and with main gear 9 and intermediate speed gear II also carried thereby. Such sleeve and gear assembly is shown as journaled upon the fixed countershaft by means of anti-friction bearings 80, 80'.

When the slidable assembly carrying gear I3 is in the forward drive (left hand) position previously described, the low and intermediate speed and direct drives are rendered effective or ineffective under the direct control of the clutching means contained in the assembly best shown in Figure 2a.

The main clutch centrifugal operating means The centrifugal engaging elements of the main clutch, comprise slidable flyweights ill (Figures 2a and 4) which are movable outwardly only when rotated fast enough'so that their centrifugal force overcomes the resistance of springs BI, which urge the flyweights inwardly, and springs 62 which urge toward released position the clutch element 86 against which the forces generated by the fiyweights react. The flyweights do not react directly against the clutch element, but serve to urge the rollers 63 trapped in the fiyweights outwardly and roll them along and between the surface of clutch element 66 and the opposed inclined faces of suitably positioned cam lugs 65 secured to the inner surface of the rear bell section 69. Member 69 forms a continuation of and constitutes with element 2 an enclosure as well as driving member for the drum, and is secured to element 2 by shouldered cap screws 10, as a result of which these members turn together, but the rear section 69 will be seen to be limitedly movable axially independently of the forward flywheel section 2 against the resistance of springs II trapped beneath the heads of the shouldered cap screws.

Upon sufllcient outward movement of the rollers 63 under the influence of the flyweights, due to. increased speed of the drive shaft, pressure plate 66 is forced into engagement with a clutch facing 61 carried in opposing position by the surface of drum 4, a similar clutch facing 88 being afllxed to the opposite face of the drum and adapted to be forced by such pressure into engagement with the inner face of the front casingflywheel section 2. A spring ring 269 is shown as interposed between the drum and the pressure plate I14 by which the last mentioned clutch facing is directly carried, to cushion the engagement of the centrifugal clutch againstFchatter." Driving engagement yet limited relative movement between the drum and clutch plate I14 is permitted by the loose interfitting of a notched flange I14] of plate I14 with a toothed driving ring 2I5, iixed, with the edge of an associate or auxiliary actuator diaphragm I13, to the drum 4, the ring and diaphragm being fixed together and to the drum, as by welding. The purpose of this auxiliary actuating means will presently appear.

The thrust reaction upon application of the clutch in the manner described is taken by the shell 59 which as previously stated is axially movable under such axial thrust in this direction, to compress the springs 1|. The total combined pressure of springs II is equal to the maximum clutch pressure required; and the degree'of movement permitted the shell by compression of these springs is suilicient to allow the' flyweights to move outwardly into engagement with the inner surface of the annular chamber in member 66 in which they are housed. When stopped by this surface they are maintained in circumferential alignment, that is. equi-distant from the axis of the assembly, and so cannot upset the dynamic balance thereof. The degree of movement allowed the flyweights by reason of this arrangement and the presence of springs 'II also insures uniform and proper clutch engagement regardless of wearing away of the facings, or any inaccuracies, differences or changesin the dimensions of the parts due to wear or other cause, as the weights may always move out until either their full centrifugal force at the instant considered is efiective to apply the clutch, or they are stopped by the rim flange of element 66, at which time the degree of movement is ample to apply the stress of springs 1| to the clutch despite any wear which may have occurred.

Use of the angular lugs 65 to take the reactive thrust upon application of the centrifugal clutch engaging means also permits the pressure plate 66 to be moved sumciently far to take care of all wear without variation of the ratio of clutch pressure to centrifugal force, so that it is never necessary to adjust the clutch for wear.

The drum 4 is journaled or supported upon the projecting end of the transmission shaft 55, at the forward end on bushing 13, and at the other end is riveted or otherwise afllxed to a hub 14, keyed as at 15 to a sleeve 11, which is integral with the gear 8 and journaled in the forward wall of the housing 1 in an anti-friction bearing 18. S eeve 11 and hub 14 are closely interfitted as at 16 to provide a liquid seal. It will be seen that rotation of the drum by reason of its securance to the driving elements by the centrifugal clutching means just described revolves gear 8 and so the low speed gear I! through gear 9, thereby transmitting the drive through gear I! (when in forward position) and overrunning clutch I6 to the driven coupling Separate and relative adjustment of both the, initial engagement speed and full engagement speed of the centrifugal clutch applying means is obtainable by varying with relation to the masses of the flyweights 60 the combined return tension of springs 6I-62, which maintain the fly weights in the inner position as well as retract the thrust plate 66, and by varying the angularity of the thrust element ,65. The springs BI--i2 prevent outward movement of the flyweights until the driving member attains a predetermined speed. Their resistance is such as to allow sufficient idling speed for the engine, and also preferably permits the engine to attain a speed establishing reasonably high torque eiiiciency before incipient engagement takes place, since the torque output of an internal combustion engine is inherently low at low speed. This idling speed isalso preferably so adjusted as to be suiiicient. particularly in winter, to allow warming up the engine at more than normal idling speed without instituting incipient clutch engagement and starting the driven element or vehicle. It will be understood however that if it is desired to race the engine without driving the car or driven element, it is only necessary to shift the assembly I3 to the neutral position, (in which it is shown in Figure 2b), thus unmeshing the gear I3 as well as disconnecting the driven sleeve 49 from the shaft 55.

The wet clutches The low speed drive is maintained so long as the clutches 5 and 6 remain disengaged. Engagement and disengagement of such clutches is effected by a fluid medium (such as oil) under the control of governing means presently to be described. The clutches themselves are shown as of the multiple disc type. Clutch 5 will be seen to be made up of driven plates IBI keyed to the common driven web I55 of both clutches 5, 6. The plates are rotatable with and axially movable relatively to the web in the well known manner.

Driving plates I63 are similarly keyed to a collar I18. A sub-pressure plate IBII is grouped and keyed with plates IGI and movable by fluid means presently to be described to engage the clutch,

by clamping together the plates I6lIB3 to lock the web I55 to the collar I18.

Collar I18 constitutes the driven member of an overrunning clutch, the rollers IiIII of which are trapped in a cage I19 which also rotatably supports collar I18 when the latter is running free. Element I18 is drivable through rollers I by a central drive hub I11, which is keyed as at I15 toa sleeve I15 rotatable on the driven shaft and rigidly carrying within the housing 1 the second speed gear III. The central web I55, constituting the driven portion of clutch 5 as well as of clutch 6, is supported by and connected to a hub I5I which is in turn keyed as at I81 to the transmission shaft 58. It will accordingly be seen that when clutch 5 is engaged, (the main clutch of course being also engaged so that drive is imparted to the drum) 9. second speed drive is established which may be traced from drive shaft I and casing 2-59 through the main clutch and drum I to sleeve 11, through gears 8, 9, II and I0, overrunning clutch I19, which looks when its driving portion I11 is turned faster than portion I18 would otherwise turn, thence through clutch 5 and driven web I55 to the transmission shaft,

which being then turned faster than gear I3,

causes overrunning clutch IS in the hub of that gear to release and overrun. Driven sleeve and coupling 495I being clutched to shaft 56 through teeth 52-53, the second speed drive is completed in the manner described, upon the engagement of clutch 5. Such drive picks up the driven sleeve without any necessity for disengaging the low speed drive, which is immediately.

rendered ineffective by the overrunning clutch The driving connection between the driven web plate I55 and the driven shaft is preferably a resilient one. Cushioning is effected by means of a plurality of coil springs I84, (Figures 2a and 1) trapped in windows in the central portion of the web plate proportioned to receive them. The edges of such windows drive the springs, which in turn drive the hub II which is provided with a projecting portion I55 cooperatively slotted to receive the springs and the drive transmitted therethrough. The springs are held in position by an annular housing formed by cupped flanges I55 secured to the opposite sides of the web plate I55 and projecting beside the springs, as well as into sealing engagement with the sides of portion I55. The portions I55 will be seen to thus provide sealing means against cross-communication between chambers I53, 255.

Clutch 5 will be seen to be similar in construction to clutch 5, the driven plates 2532M255 being similarly keyed to the same driven web I55 and arranged to cooperate with similarly interfitted driving plates 205, which are in turn keyed to the driving hub 325 secured to drum 4 by rivets 325. Element 325 is formed in two parts, shown as splined together, for purposes of assembly. It will be apparent that upon engagement of clutch 5, the driven web I55 is directly coupled to the drum and turned therewith, the drum being in turn clutched to the drive shaft as an element of the main clutch, and driven web I55 being directly connected to the driven shaft at I51, direct drive is established.

The fluid actuating means allows disengagement of clutch 5 upon engaging clutch 5, and it will be seen that one of the driving plates I52 of clutch 5 is secured to the roller cage of the overrunning clutch which is interposed between driving hub Ill and the clutch 5. The rollers, and accordingly plate I52, are capable of only limited circumferential movement with respect to the huh I". The drag of the plate I52 in the drum urges the rollers towards wedged position, thus eliminating necessity for a torsion spring in the overrunning clutch, while the use of such overrunning clutch prevents turning the remaining driving plates I5I when clutch 5 is disengaged, eliminating the heat generation and power loss from friction drag normally inherent in multiple disc clutches from the plates rubbing against each other or rotating through a liquid when running freeonly the plate I52 being rotated relatively to the others when the clutch is disengaged. Plate I62 generates very little heat while running free, yet has sufficient capacity to hold a vehicle against coasting on hills, since with clutch 5 engaged plate I52 resists forward coasting of the vehicle in second gear, but the capacity is assumed to be insufficient to transmit the full driving torque of the engine without excessive engagement pressure. If, however, the torque to be passed did not require the use of more than a single plate, the overrunning clutch could of course be eliminated.

The clutches 5 and 5 are urged toward released position by spring portions 255 which are formed as integral laterally bent prongs on the peripheries of the plates I50, I53 and 205. These spring tongues, as best shown in Figure 6, are bent in opposite directions on adjacent plates, so that the point of each tongue abuts the heel of the next, and yieldably space the plates at desired intervals, acting to return the clutches to released position when the pressure is released.

Air cooling means for its mechanism is also provided by the arrangement of the multiple clutch assembly. One of the prime reasons for so constructing this device as to isolate the clutching elements from the torque chang ele- Controlling means for fluid-operable clutches Primary control of automatic shifting is effected by centrifugal governing means II, by

which the operation of the fluid actuable clutches is controlled through valving apparatus presently to be described. A belled sheet metal portion I35 is mounted on the driven shaft 55 and rotatable therewith within the housing I, together with an opposed and relatively slidable interfltted bell portion 53. Such opposed bell sections have convergent tapered portions near their peripheries and enclose radially slidable flyweights III.

The angularity of the inclined outer thrust portions of flyweights I3I and of the bell 53 increases in steps, as at I35, I35. Th flyweights are normally urged inwardly by springs I33, as well as by springs I3|--I85 (Figure 2b) and are retained in suitably spaced relation by a pronged guide ring I32, the prongs of which are slidably fitted into radial apertures I33a in the flyweights. Springs I33 will be seen to be formed of wire bent to substantially L-shape, with arms projecting substantially tangentially from the outer surface of each fly-weight to engage the interior of the bell I35 (Figures 2b, 8a and 8b). Upon rotation of the driven shaft fast enough to cause the centrifugal forces of fly-weights III to overcome the resistance of springs I33, I35, the inclined faces of the flyweights will be seen to react against the slidable bell 53 to urge the same to the left as viewed in the drawings.

Carried and movable by the bell 53 is a cam or eccentric 82 which is arranged to rotate in the path of any one of the offset portions 55-235- I35I55 of a double armed lever 55, depending upon the axial position which the eccentric occupies, which is in turn determined by the governor. When the parts are in the position shown in the drawings, the eccentric, in the right hand position, is aligned with the portion 54 of lever 55. Accordingly at the first rotation of the driven shaft the eccentric immediately throws lever 55 to the left and to the position shown in Figure 9. The lever 85 is in turn connected, through. its supporting shaft 55 and an arm 51 mounted on said shaft and carrying at its end a rounded portion 58, to a control valve 55, the function of which will presently b described, It will be seen. however, that this valve is movableto different positions by the eccentric 82, de-

pending upon which of the offset portions of the lever 85 the governor-controlled eccentric is in alignment with. The operation of these parts will be taken up in describing th valving means which they control.

Pumping and valving means for fluid-operable clutches point, while being smaller than the pump chamber deflned by such ring. A suction chamber 88 is deflned upon one side of the center line passing through such point of tangency, and a pressure chamber as 88 on the other side thereof. Chambered recesses III8I8I are formed in the pump body in substantial radial alignment with and connected to the suction and pressure chambers 88, 88 respectively. Centrifugal force is relied upon to initially move vanes 85 into contact with the stator ring, but after fluid pressure has been developed they are maintained in such contact by such pressure in a manner presently to be described. Fluid is drawn by this pump from the bottom of the liquid-filled casing through a strainer I85 arranged in the mouth of intake pipe I81. The strainer will be seen to be accessible through the drain plug I88 in the bottom of the casing.

The screen may be arranged to drop from the casing upon removal of the plug, thus automatically reminding the service man when draining i the fluid medium in the casing that the screen should be cleaned, a necessary operation which might otherwise be overlooked.

The fluid is drawn throughintake channel I88 chamber IIII, whence it passes through outlet port II8, Into relief valve chamber III. A constant predetermined pressure is maintained by the spring pressed valve II2 contained within chamber III and normally covering the relief port II5, the tension of the spring I It being such that the degree to which the port H5 is uncovered by excess pump delivery is variable to maintain constant the pressure of delivered fluid. The spaces 242 beneath the vanes are connected as by a channel 245, (Fig. 11) to the chamber III, the vanes being thereby urged outwardly by the fluid pressure of the pump discharge. It will also be observed that the fluid pump is one adapted to supply fluid at a constant non-pulsating pressure and with complete quietness of operation. Noise from any elements of a motor vehicle drive is of course very objectionable, and with pumps of the gear type as well as of many other constructions, some noise is inherent to their operation. The manner in which the pump rotor vanes are urged outwardly by the fluid pressure will also be seen to eliminate the use of springs for such purpose and be far more dependable.

From chamber III the pressure fluid passes through passage H6 in a valve sleeve II1, past a valve I I8 into a chamber I is formed by a recessed portion of the valve I I8, and thence through e I20 in the pump body 80, and through e-l2I in the sleeve I22 of valve 89 into a rd portion I23 of the valve. Valve chamber I28 communicates by means of an opening I24 with the hollow interior bore I25 of valve 89, through which the fluid passes, emerging through opening I28 and valve chamber I21 to port I28 .whence it is exhausted through the slot I28 and relief port I80. It will be seen that when the valves 88--I I8 are in this position, th'e pressure fluid is not in communication with any clutching elements.

Upon attainment of a predetermined speed by the driven shaft, eccentric 82 is moved to the left, as viewed in Figure 2b, by the governor means previously described, until it is in axial alignment in slidable contact with the stator ring 86 at one with the offset portion I88 of the stepped arm 85. The next rotation of the eccentric rocks the arm 85 to the right, thereby moving the valve 88 in the same direction, as viewed in the drawings (Figure 10) to the extent of one notch defined by detent pockets I42. This movement is of course imparted to desired degree by suitably proportioning the throw of the eccentric and the extent of projection of the toe I39 of the lever, the valve positions being yieldably maintained by a spring pressed detent as I, which engages the pockets I42 in the slidable valve. The size of the inclined sides of these pockets and the locations of their centers are preferably such that a slight excess movement, beyond that induced by the eccentric, is imparted by the detent, thereby moving the lever arm slightly clear of the eccentric at each stepand preventing further wear and contact.

the right in the manner indicated, fluid after' passing through the hollow interior I25 of the valve, as also previously described, is delivered by valve chamber I21 to port I48, with which port the valve chamber I21 is then aligned, relief port I28 now communicating with a chamber I8I of the valve 88. After passing through passage I48 the fluid flows through a chamber I44 of the valve I I8, and thence to an annular chamber I45 which surrounds the transmission shaft 56 in registry with a radial pass'ag'e I41 therein which communicates with a, longitudinal conduit bore I48. Through bore I48 the fluid is conducted to another radial passage ;I '48 opening at the surface of the shaft within the clutch assembly portion (Figure 2a). From passage I49 the fluid is conducted through annular chamber I50 and port I52 to a pressure chamber I53, defined by the web I55 on one side and a flexible diaphragm I54 on the other. The diaphragm is peripherally sealed to the web and at its central portion is slidably' {sealed to theh'ub I5I to close the chamber. Flow of'fluid into the chamber I58 through other ports force to compress the clutch plates and lock the clutch 5, to establish the second speed drive in the manner previously described. The pressure chamber I58 is adequately sealed at the inner edge by snug engagement of a sealing portion 2| I with the hub I5lon the one hand and similar engagement between the cupped flanges I and the sides of the enlarged portion I85 of the hub which supports the driving springs I84, as stated.

Simultaneously with delivery of fluid under pressure to chamber I53, fluid is delivered to an auxiliary applicator for the main clutch, presently to be described. The fluid passes from channel I48 in the shaft through radial bore I65 to an annular chamber I58 bounded on one side by a slidable two-way valve I61, which is by pressure in chamber I66 movedto the right as viewed in Figure 2a, to connect port I58 with that chamber and allow the fluid to flow into a chamber I12 of the fluid-actuable applying means for the main clutch, passing through channel "I.

As the driven machine gathers speed in second through connecting passage I99.

orintermediate torque drive the increased rate of rotation of the driven shaft causes the flyweights I 3| in the governor I1 to move farther outward and by engagement with the steeper portions I35-I31 of the bells 83-I38 move the eccentric I32 farther to the left and into alignment with the toe I89 of arm 85. The rotation of the eccentric then immediately moves the arm and so valve 89 still farther to the right, to the third position, registering chamber I21 with a second port I99, through which the pressure fluid may in like fashion be delivered, after passing through communicating passages I92-l93, to another annular chamber I 94 also encircling the driven shaft within the pump body 90, and spaced and isolated from annular chamber I45.

At the same time the pressure chamber I53 of clutch is connected to atmosphere to allow the exhausting of pressure fluid from and disengagement of that clutch, by movement of valve chamber I9I into registry with port I 49 (which as described above communicates with pressure chamber I53) valve chamber I9I establishing connection between ports I40I28, and the latter venting to atmosphere through passages I29I3II.

The pressure fluid delivered to chamber I94 passes through passages I95I95-I91 in the transmission shaft 55, and through an annular collecting chamber I98 with which radial passage I91 communicates, to pressure chamber 295, By expanding the bellows 2III and so compressing the plates of clutch 5, previously described, such clutch is engaged to couple the driven web I55 directly to the drum 4. Drum 4 being clutched to the driving shaft by the main clutch, direct drive is of course established through the cushioning springs I84 to the transmission shaft, and to the driven coupling 5|, since in all forward speeds the sleeve 49 by which that coupling is carried is clutched by the teeth 52-53 to the transmission shaft.

It will be seen that expanding the diaphragm I13 provides the required pressure upon facings 5158, to establish engagement of the main clutch irrespective of the rotational speed and of the centrifugal actuating means 3 at such time.

Upon the delivery of fluid under pressure to chamber I98, the slidable valve I51 encircling the forward end of driven shaft 55, is moved to the left as viewed in the drawings, to uncover the port I59 communicating through passage In with pressure chamber I 12 defined by the forward face of the drum and the bellows I13. Pressure fluid is thus delivered to this chamber concurrently with its delivery to the direct drive clutch 5, and the resultant expansion of the diaphragm I13 applies the required pressure to the clutch plate I14 to fully engage the main clutch independently of the centrifugal actuating means 3.

The same will be seen to be true upon delivery of pressure fluid to second speed clutch pressure chamber I53 through the conduit bore I45, as above stated. At such time the delivery of pressure fluid to pressure chamber I12 through passage I55, valve chamber I55 and port I59 similarly engages the main clutch fully, irrespective of the centrifugal applying means. The valve element I61 thus serves to prevent communication between the two pressure channels I49 and I95 and maintain the isolation of these channels and then connected pressure chambers I53-209 respectively while yet admitting the pressure fluid from either to a common pressure chamber.

The release of the main clutch from fluid pressure engagement is aided by opposing pressure of a pronged or star shaped flat spring 218, and by the resiliency'of the diaphragm itself. The pronged ends of spring 218 bear against and hold in position the friction facing plate I14. A retaining plate 2" is also arranged within the facing plate I14, and a stop ring 212 by means of which part of the engaging pressure of the diaphragm may be blocked off without losing any of its total flexibility. This will be seen to permit regulation of the fluid-effected engaging pressure in co-relation to the springs 1 I.

The chambers I59 and I95 formed in the hub I5I are isolated from each other by a reduced diameter within the hub, which is closely fltted as at 2! to the shaft 55. Seal points are further formed at the outer ends of the hub by closely fitted surfaces as at 2 I 9-225. Any liquid which may leak past sealing points 2I9 and 220 tends to fill drum 4, the excess being conducted back into casing 1 through spaces 219280.of the gear sleeves, thereby flushing and lubricating the bearings thereof, and through space 28l and a slot (undesignated) in thrust washer 282. Sufiicient liquid is allowed to flow into the drum in the manner indicated to keep the drum filled, soj that any fluid pressure upon diaphragms I54- 20I created by centrifugal force is virtually equalized on opposite sides of such diaphragms.

It will be understood that when the driven shaft again slows to a predetermined speed, the direct drive clutch is released'and the intermediate clutch 5 engaged. This occurs with return of valve 89 to the second or middle position, which is effected by the throw of the eccentric flange 82 against a step 239 of the arm 85, which is axially aligned therewith when the governor member 83 is in the intermediate position. In such intermediate position the pressure chamber 280 of'the direct drive clutch 5 will be seen to be open to the atmosphere by connection of the connecting port I90 to passage 2I1, opening to the air within the casing around the end of the operating stem portion of the valve 59, thus allowing the fluid to escape and this clutch to disengage.

Upon a still further reduction of the speed of rotation of the driven shaft, the eccentric flange 52 is returned by the governor to the right hand position shown in Figure 2b, aligning the same with the step 84 of arm 85 to throw the valve to the first or left position, as viewed in Figure 10, thereby also connecting pressure chamber I53 of clutch 5 to atmosphere through passages Over-control of fluid-operable clutches Personal over-control of the torque ratios by direct driver supervision of the several clutches is provided for, through means enabling changing the position of valve II 8, which has previously been considered as occupying its normal or left hand position as viewed in Figure 10, in which position it offers no interference with operation of the parts in the manner previously described. This valve may be moved, however, to either of two other positions, in the first of which or middle position, (one step to the right) it provides direct connection between the ports II5-l45, cutting off the flow through port I28 to valve 89. This connection is provided by valve chamber II9, which, when the valve 8 is moved one step to the right, bridges the ports Iii-I48. Such degree of movement of the value is effected, in the shown embodiment, by means of a button .221, upon depression thereof to the extent indicated by the arrow 235 or until it abuts the larger of the two interfltted buttons (226). In

'vehicular installations this double button unit is preferably installed upon the floor boards of the vehlcle in a convenient location for foot oper- 'ation, as at the approximate position normally thus urges the valve H8 a predetermined distance (235) to the right (to the middle position), while heavier pressure is required to move the valve an additional distance (231) farther to the right, such movement being communicated to the valve by a Bowden wire conduit assembly 22I-222, the wire directly connected at one end of the valve through an adjustable guide nipple 223 in the side of the casing 1, and at the other end connected to the smaller central button by means of a stem 3, which is guided by a sleeve 22!. Adjustment of the nipple 223 which is threaded into the casing, permits endwise adjustment of the valve IIB to properly fix its initial positions, such movement also moving the entire unit and connecting conduit (or flexing the latter).

Upon movement of valve H8 the first unitary distance to the right, to the middle position, port 5, as previously stated, is directly connected to relief valve chamber II I, and assuming of course the gear assembly I3 to be in the forward position, pressure is delivered to the intermediate speed clutch 5 through the chamber III), in the manner previously described. It will be seen, therefore, that as long as the button 235 is held in this position (under light pressure applied by the operator), the transmission will be held in intermediate torque drive. Passage I20 is at the same time open to atmosphere by virtue of the reduction of the left end of valve H8 to which the actuating wire is connected. Further, any passages with which the valve portion I21 may be in registration are thus now vented to atmosphere.

It will be seen that if valve 89 is already in intermediate position, valve II8 merely short circuits the same when moved one step to the right in this fashion, whereas if valve 89 is in the right hand position, that is, with the central bore I25 communicating through recess I21 with the direct drive clutch applicator chamber 250, such clutch (6) may be released by disr passes the port 6, thereby allowing the pump pressure to discharge from chamber III directly to atmosphere, simultaneously connecting passage I45 and so' the second speed clutch to atmosphere through port I) and passage 2I'l,

thereby opening both clutches 5, ii and main clutch fluid pressure chamber I12 as well as venting the pump pressure to atmosphereand causing disengagement of both clutches 5 and 8, so that the only drive which remains effective is the low gear ratio (high torque) drive through gear I3, which drive remains operable through said gear and the centrifugally actuated clutch.

In vehicular installations the springs 23i)-22l are preferably so proportioned that the mere weight of the operator's foot is suflicient to move the valve M3 to the intermediate position, while distinctly greater pressure, that is, a definite push, is required to throw it to the right hand position in which it establishes low speed drive.

It will be observed that the pump and control valve assembly is floated upon and carried entirely by the driven shaft 55, although held from rotating therewith by an arm 226 extending laterally from the housing into engagement with a lug undesignated) projecting from the side of the casing 1.. The close fit of the chambered manifold portion encircling the shaft can thus be affected by no forces (such as deflection of the shaft) which might cause wear, other than the weight of the assembly itself.

When the gear and roller clutch assembly I3 is in the forward (left hand) position in which we have thus far assumed it to be, a relief port 31, which is connected to the fluid pressure supply source through a passage 249 establishing communication between such source and the valve chamber I23, is closed by means of a plug valve 38 which is maintained closed by shifter rail 3| while the latter is in the position it occupies when gear assembly I3 is in forward position. The rail is so grooved, however, as at I, that when the gear assembly I3 is moved away from the forward position to either neutral or reverse, valve 36 is free to move under fluid pressure to open the escape port 31 and thus prevent the application of fluid pressure to either of the clutches 5, 6 when the manual control 22 has been moved to establish neutral or reverse drive condition.

Suction torque control A further control element influencing the automatic shifting of valve 89 to determine the torque ratio under automatic control may be provided in the form of means responsive to the degree of suction in the intake manifold, where the transmission is used in conjunction w th an internal combustion engine. Such torque control mechanism constitutes an adaptation of the Lassiter suction torque control as disclosed in his application Serial No. 756,903, filed December 10, 1934.

A suction chamber portion 25I of substantial size Figure 3) is connected to the intake manifold as by means of the conduit 255. A regulatabie valve screw 26! is provided in the suction line. The large chamber 25I constitutes a storage or delaying tank, while the piston 251 is slidable in a reduced upper cylinder portion 256, directly connected to the side of the casing 1 in the shown construction, as by means of the flange 252. The tendency of the suction developed in chamber 25I to draw down the piston 251 is yieldably resisted by a spring 258. The

' the addition of the letter a.

thrust of the spring is imparted through a stem 259 to an arm 260 carried by the projecting end' of a shaft 26L which extends laterally through the casing I between governor and pump assemblies II-I8, as shown in Figs. 2b and 9, carrying yoke arms 2622G3 pivotally connected with a collar-265 arranged to oppose movement of eccentric and governor bell assembly 8283 to the left, an .anti-friction thrust bearing as 261 being interposed. It wi11 be seen that when overcome the various degrees of opposition of the spring 258. So also when the vacuum falls away sufficiently the resultant imposition of the force of spring 258 may be suflicient to overcome the centrifugal force of the ilyweights and return them to a more central position.

Modified shiftable gear and control arrangement The mechanically shiftable gear and overrunning clutch construction designated I3 in Figure 2b may be modified in order to provide the braking effect of a high torque gear ratio when desired. Such a modified construction is shown in .Figure 16, with which the remaining apparatus may be used in the same or substantially the same form. In Figure 16 parts equivalent to those shown in the previous views have been given like reference characters distinguished by As shown in that view, thetransmission shaft 56a may be similarly piloted in the driven sleeve 490, which sleeve is splined as at 49b, such splined portion slidably supporting an interfitted hub 450. with 4 which are slidable an overrunning clutch assembly I6a and a ring gear I30. constituting the.

driving element of the overrunning clutch. The

entire unit is similarly slidable by a shifter fork unit are clutchteeth 52a engageable with clutch teeth 53a mounted on the collar 54a of the centrifugal governor unit Ila. A separate web 330 is rigidly connected to the ring gear member I3a at its end opposite clutch teeth 52a, and is at its inner extremity splined similarly to hub portion 45a for cooperation with either of the spaced splined portions lilo-248a carried by the driven sleeve 49a, to lock the gear to the sleeve and enable the transmission of reversible drive through such gear. The web 330 is shown as somewhat spaced from hub 45a and secured in the end of the gear by the interfitting of splined portions, as at 33I, and by peening over the gear member outside the web as at 321.

The clutch teeth 52a will be seen to be so spaced from the body of hub 45a, and so carried by an overhangingsupporting portion 328, that the unit after passing through the position in which teeth Ma -753a. are engaged (while the splined hub of web 330 remains free of splines 492:) may be moved still farther in the same 411- recticn (to the left in the drawing) to free teeth 53a and allowvthe latter to turn freely within the space 329. The parts will also be seen to be so proportioned that when the unit is in this last-described position web 330 is also engaged with splines 49b, while gear I20. is wide enough to provide for full meshing of gear I30 therewith in either of the last two positions. When teeth 52a-53a are engaged and web 325 is free of splined portion 49b, drive may be transmitted to the driven sleeve either from low speed gear Ila through overrunning clutch IGa and hub 45a to the driven sleeve 49a, or the sleeve may be driven directly from transmission shaft 55a. through splined connection 550. to hub 54a and through clutch teeth Sim-52a to hub 45a. The drives through clutch teeth 5211-5311 are of course at higher speed than the drive through gear Ila, and cause overrunning clutch IGu. to release, a1- lowing hub 45a to overrun the gear I311.

When the gear and overrunning clutch unit I3a.I6a is moved all the way to the left and teeth 520-5311 freed as above described. en agement of the gears I2ol3a being maintained and the web 330 being then directly keyed to the driven sleeve portion 49b, reversible high torque (low speed) drive may be imparted to the driven sleeve through gear I2a. A reversible drive is thus provided which prevents free coasting of the vehicle and imposes the braking effect of the engine so long as the main clutch is engaged, while the lower torque (higher speed) drives are ineffective by reason of the disengagement of clutches 52a53a. It should be observed, however, that under such conditions the transmission shaft and pumping mechanism will continue to be driven by reason of the viscosity drag of the wet clutches, which drag is always sufficient to turn the freely rotatable shaft 561: when disengaged from the driven sleeve. Thus even were the engine stopped or slowed to such extent as to releasethe centrifugal clutch operating means, with the clutch portions 52a53a disengaged in this manner, the auxiliary applicator would maintain engagement of the main clutch as long as, or establish such engagement as soon as, the shaft 56 reached sufiic'ientspeed to cause the pumping mechanism to supply pressure to the auxiliary applicator.

When the slidable unit is moved to the rearmost position to key the web 330 to splined portion 2480 of the driven sleeve,,reverse drive is established directly through the web from driven gear I3a, which is then meshed with reverse idler I5a, while all forward drives are disengaged. The transmission shaft of course continues to turn in the forward direction, as in the previous embodiment, under either viscosity drag or the action of the wet clutches, (depending upon the speed of the shaft 56) pump priming being thus maintained.

Whichever embodiment of slidable gear and overrunning clutch unit is used, the plate I62 of the intermediate clutch unit 5 may or may not be arranged on the cage of the overrunning clutch or its hub, because the braking effect of lower gears on hills, etc., has been found to be unnecsary, with present day motor vehicles. The two directional drive arrangements provided in each case in the present disclosure are to meet the public demand for such condition due to the belief in its necessity. If the overrunning clutch cage in the intermediate drive be relieved of this connection, regardless of whether the first embodiment Or that of Figure 16 is used, the intermediate clutch 5 may remain engaged While direct drive clutch 8 is also engaged. Under these conditions the unreduced portion 290 of the valve 89 may be omitted and the exhaust passages I28--l29l3ll eliminated or closed. After such change it will be seen that the pressure fluid will continue to be delivered to the intermediate clutch while also being delivered to the direct drive clutch 5. An advantage of this method of operation would be the elimination of slipping action upon transfer of drive from one clutch to the other. With such change it will also be seen that no communication need be provided between fluid channel I95 and the main clutch fluid actuating chamber I12. Element I51 would then preferably be flxed in longitudinal position rather than slidable on the shaft 55, to prevent cross communication between chambers lIi--l 98 while remaining in the position inwhich it is shown in Figure 2a to allow constant energization of the main clutch fluid controlled actuator from the second speed fluid channel IIB during those pe-' riods when either the clutch 5 or both clutches I 5 and 6 are engaged.

Miscellaneous features In order to remove the clutch facing 55 to replace the same, it is only necessary to lift the fingers of the spring 215 and slide the facin plate I14 from beneath this spring. The opposite facing 51 is also easily removable by removing the retaining wire or pin 293 which locks the facing plate 285 upon its supporting studs 2".

The sub-pressure plates I55-203 will be seen to have frusto-conical inner faces on their sides which cooperate with the pressure plates I592Il2 respectively. This compensates for distortion of the main pressure plates, by allowing them to bow outwardly towards the center while yet maintaining the application of pressure at the mean diameter of the interspaced clutch plates, which is essential for proper operation and wear. This feature materially reduces the cost of construction, since otherwise the main pressure plates would have to be at least three or four times thicker to adequately resist the bowing tendency. The flexible pressure plates also serve as antichatter springs, being preferably formed of suitable spring-material and cushioning the clutchapplying pressure, as will be apparent, by their flexure in the manner described.

The ports or passages I52 and I99 through which pressure fluid is fed to the clutches 5-5 are restricted, and so proportioned in relation to the type and operating viscosities of the fluid employed that a predetermined time interval, ordinarily approximately three seconds, is required for the fluid to pass through ports I52-I99 and fill the pressure chambers l53200 to fully engage the clutches 5 and 6. This provision is made for the reasonthat in the normal operation of a motor vehicle by most drivers, the length of time in which each of the lower speed ratios is maintained during shifting is practically uniform, whether the vehicle is accelerated rapidly I or slowly, the only difl'erence being in the degree of throttle opening. In other words, while the time interval is approximately the same in flrst or second speed, the driver. if in a hurry, ordinarily speeds up the engine faster, but does not leave either first or second speed drives engagement for any longer period of time. The introduction of the time factor by the restriction of the feeding ports I52, I99 therefore allows the driver a similar choice in driving a vehicle equipped with our automatic transmission. He may accelerate, for example. on one occasion to 5 or 10 miles an hour in low speed drive within the three second period, while on another occasion he may accelerate to perhaps 25 miles per hour, by merely speeding up the engine more rapidly. The provision of such a time interval alone however would not be suflicient for automatic control, since at vehicle speeds below a certain range it is essential for eiilcient operation that low or intermediate speed drive be maintained for the entire period during which the vehicle is traveling below such speed range. For this reason the speed sensitive control is provided in the form of centrifugal governor I1.

Provision of restricted feed ports proportioned to provide a predetermined time interval for clutch engagement when the fluid is at,normal temperature introduces another important advantage, since as a practical matter it is necessary to use a fluid whose viscosity varies under temperaturechanges. Therefore, when warming up or first starting the engine in cold weather, or low temperature conditions, the liquid being of greater viscosity requires a longer time to pass through the ports I52-I99 and apply the clutches, accordingly allowing for running in the lower gears for a somewhat longer period before direct drive is established, thus easing the load upon and assisting in the warming up of the engine. The areas of the ports are such, however, as topass the fluid within the desired interval after it has warmed up sufllciently to attain its normal working viscosity. The restricted ports I52-I99 perform the further function of preventing sudden or Jerky application of the clutches.

Additional delay in initial engagement'is also provided by the spring means GI, 52 which prevent the flyweights 60 of the centrifugal clutch applying means from moving outwardly until the driving member attains a predetermined speed.

This speed is high enough to allow idling the engine at a, rate sui'iici'ent to permit warming up the engine at a reasonable speed without engaging the clutch. This is of course particularly important in a motor vehicle, and the rate may" be somewhat higher in winter weather. Further, since the torque capacity of an internal combustion engine is inherently low at low speed, it is desirable that it be brought up to a speed approaching maximum torque efliciency before the clutch begins to take hold. The diiference between the speed at which clutch engagement begins and that at which it transmits full torque should, moreover,- not be great. I a

The use of separate springs I3l--I8I resisting axial movement of the governor bell 83 and its separate angles enables independent adjustment of the rotative speeds at which valve 89 is shifted to each of its positions by the governor. The bell 83, which resists outward movement .of the flyweights and is moved thereby, is provided with two angularly disposed faces, as above stated. The first, I35, is more gradual than the outermost steeper portion I36. Outward movement of the flyweights I3I along the more gradual portion is resisted by springs I33 and I, while the parts are so proportioned that when the flyweights reach the steeper portion Ill, spring I34 is fully compressed and the additional resistance of springs I88 opposes further outward movement of the flyweights along the steeper portion I39, and the resultant valve movement to the third or direct drive position. It will thus be seen that lay-changing (relatively) the angled portion and/or the tension of springs "3-434- I 88, the speed or relations of speeds at which shifting to intermediate or direct drive is ef- [acted by the governor may be regulated within wide limits.

The form of governor shown, comprising a. symmetrical housing enclosing sliding weights, not only provides much greater compactness than a construction employing swinging or pivoted fly-weights, but eliminates projections which would otherwise agitate the liquid and cause heat and frictional losses, and further prevents the interference with normal governor operation which would be caused by the liquid;

The operating means IQ for the valve l6 also enables complete disengagement of the driven elements from the driving elements, equivalent to declutching the drive of a motor car having manually operated clutch and transmission portions rection, and if it were at this time coupled to shaft 56, the latter would be very strongly urged against reverse by the viscosity drag of both clutch units 5 and 6, particularly because the clutch driven plates would add their reverse velocity to the forward velocity of the driving plates. By virtue of the disconnection of sleeve 4-9 from shaft 56 however, the entire clutch assembly with the exception of the single plate I62, whose drag is negligible, is allowed to rotate freely as a. unit in the forward direction.

Uncoupling driven sleeve 49 from shaft 56 also enables the pump tofunction with the mechanism in neutral or reverse. With the shaft 56 so disconnected, advantage is taken of the viscosity drag of the. clutches to cause the pump to conarranged in the mannernow regarded as conven tional. Disengagement is effected by moving the valve H8 to its low speed position in which the fluid pressure is removed from all clutches and particularly the pressure chamber I" of the fluid pressure applicator for the main clutch. When such condition obtains the driving shaft I can be sufficiently reduced in speed to release the main clutch from its centrifugal pressure engagement or if desired can be entirely stopped whether or not the driven members continue to rotate. This is due to' the fact that low gear l3 cannot be driven in a forward direction by the driven shaft, dueto the presence of the overrunning clutch l5, and likewise that the shaft 56, although connected to the driven sleeve 49 cannot drive the clutch drum 4 because of the disengagement of both clutches 5 and 6. Under these conditions therefore no back drive from the driven members can keep the main clutch at centrifugal engagement speed, thereby permitting release of the latter and total disconnection and overrunning of the driven drum 4. This constitutes a means to allow coasting, of a vehicle when desired with but slight manual effort.

As is well known, when plate or disc clutches are operated inunersed in a fluid such as oil of sufficiently high viscosity to act as, an eflicient lubricant, there is strong tendency of the plates to adhere when the clutch is disengaged, even though the .plates are. reasonably widely separated. This effect bcomes particularly pronounced with the operation of the device outdoors in winter, when the oil" or other liquid medium between the plates may become practically non-fluid. The viscosity drag so caused also increases in proportion to the mean radius of the plate engaging surfaces, and since it is',highly desirable in the interests of smooth operation, long life and efficiency that this radius be as great as possible, considerationof viscosity drag becomes of importance. With a transmission of the disclosed construction such viscosity drag is of little or no importance when the vehicle is started with the gear unit I3 in the forward position, but with s reverse the sleeve 49 is revolved in the opposite disleeve 49, the liquid would be ejected'from the pump intake and an objectionable length of time would .be necessary to again prime it upon being started in the forward direction, which eflect would be particularly pronounced in cold weather operation.

Since rotation of the shaft 56 also causes the I governor member 83 to perform its normal operations, the valve 89 further being moved to its clutch engaging positions upon such rotation of shaft 56, if the engagement of the friction clutches 5-6"'were, allowed to take place with the mechanism in reverse or neutral, the lowest or idling speed of the driving member might be too high'to permit return of the governor member 83 to the first position, which would thereby preelude forward engagement of the shaft 56 with the then stationary member 4!.

gear assembly l3 to neutral or reverse prevents such operation of the-friction clutches 5-6, while allowing the pump to continue functioning in the forward direction for the reasons stated.

It will also be seen that by housing the wet clutches in a separate drum rotating in air, dissipation of the heat generated by repeated. clutch engagementunder load i greatly aided.

It will be perceived that the suction torque control unit 2| may be eliminated without aiiecting the operation of the device in any way other than leaving such function as it performs automatically to manual control by the operator, since the control unit l9 provides means for effecting such variation or for any other contingency and the exercise of-the operators judgment.

Clutch assembly modification seen to be substantially the same in construction.

and operation as the equivalent clutches described in the previously disclosed embodiments and analogous parts will be seen to be desig-f nated bysimilar reference numerals distinguished by the addition of the letter a. The fluid pres- Provision ofrelief port 31, which is opened by movement of the sure applicator for the main clutch, however, is

fed from the longitudinal bores Ba-Ilia through passages IBa-I01a separated by an analogous slidable valve element IIi1a, which enables delivery of fluid to pressure chamber l12a from either of said passages through a port ISM, while preventing cross communication between the passages I48a-l91a. Through the port I591: fluid flows to the chamber HM and thence through passages 300, chamber 30I and passages 302-303 to the pressure chamber I12a, formed by a pair of diaphragms 305-306 forming an envelope which when expanded bears against web plates 301-303 to force clutch facings fill-60a in to full driving engagement with pressure plate 56a and the inner face of member 2a, respectively, thus locking the main clutch in like manner. Diaphragms 305-306 are sealed together, as at 303, and at their inner diameters similarly sealed, as by seam welding to a flange 3I0 of hub 3| l. The hub 3 is secured to drum 011 as by the bolts 3I2, pressure chamber 30I in the hub being sealed as at 3I3 and 3 by closely fitting the same to an inner hub 3I5 mounted on the end of shaft 55a, as upon bushing 13a.

Any fluid from the high pressure chamber 30I which may-pass the seal point 3" is concreased torque ratio, and over a greater period of time.

It will be observed that valve I61 is guarded against wear by floating the sleeve I68, in such manner that it may move radially, between ringfi.

325 and hub 2I0, by which members it is retained. This precludes the valve I01 and also the seal surfaces 220 from at any time acting asa journal on the end of the shaft 56 for the clutch drum 4, the load always being received by the bushing 13, regardless of the wear of the the sleeve I15 passing freely through the hub 10:

the s'plined portion I01 of shaft 55 passing freely through the hub I11; and the reduced end 'portion of the shaft 56 slipping through its surrounding fittings without interference.

The casing 1 is provided with bolt holes 29I in flanges 292 for fastening the same to any suitable supporting member such as a frame ducted back to the pressureless space of the drum la through a drain passage 3I6 communicating" with an annular space 3l1 (also pressureless) at the drum end of thesealed space 310'. External leakage from the chamber 3I1 is precluded by a gasket as 3I8 or other suitable means.

The web plates 301-308 are preferably constructed of spring material so tensioned as to yieldably resist expansion of the diaphragms 305-306 and aid release of the clutch when the pressure is relieved from the chamber l12a between the diaphragms. Plates 301-300 are also preferably formed with integral spring tongues at their peripheries, as M9, to cushion the main clutch against chatter, as is common practice.

It will be observed that the riuid operablev auxiliary applying means I13 for the main clutch also enables turning the driving element I from the driven element when desired. It is thus possible to start the engine by towing or pushing a vehicle in the normal manner, or by any means rotating shaft 56, so long as assembly I3a is in forward drive position, as connection is established by the fluid pressure applicator as soon as the speed of the normally driven elements is reached or passed at which intermediate or direct drive is inaugurated. Further, the auxiliary applying means maintains main clutch engagement at much lower speeds than are necessary to keep the centrifugal actuator eil'ective. Thus in vehicular installations, when, as is often the case, it is desired to drive slowly in a higher speed gear, this may be done without unduly racing the engine.

It will likewise be observed that when the unit I3 (or I3a) is shifted to neutral position the vehicle may be towed without turning over the engine, also in the normal manner.

It will be observed that in event of any tendency for the mechanism to start in direct or intermediate rather than low speed drive, due to viscosity drag in the wet clutches, in such degree, especially, as it is present in cold weather,

the centrifugal clutch provides a compensating efiect, since it is capable of smoothly bringing the mechanism up to speed, though not at inwhich may surround the multiple clutch assembly. The only requirement in the setting-up of the complete mechanism is that the axial relation between the driving shaft I and the casing 1 be maintained within reasonable limits.

If desired the ratio-changing in this invention maybe controlled in an interrupted manner such as is provided for in the previously filed application of Robert B. Aspinwall, Serial No. 706,232, filed January 11, 1934. In other words, connection may be made so that some elements under the control of the operator, such as the accelerator pedal of a motor vehicle, would haveto be released to allow changes in ratio. This may be accomplished by means of an escapement mechanism or equivalent, such as the modification illustrated in Figures 17 and 18. As shown in Figure 1'7, stepped ratchet teeth 40L 402, having inclined back surfaces are formed upon the end of valve 33. The teeth are engageable by a pair of pawl-like escapement arms 403, 404, individually swingable upon a supporting shaft 405 and one slightly longer-than the other. The shaft also carries an actuating portion 401 for the escapement arms, projecting between the arms and fast upon the shaft, while the arms, which are loose upon the shaft, are drawn toward each other and against the actuating portion by a spring 000. A bellcrank the arms of which are designated 005, II I, is fixed to the shaft 005. A spring l09 secured to arm 08 urges it against 'a stop 4I0, thereby yieldably holding the escapement arms in centered position. When so centered the escapement arms are spaced insufliciently to allow the extension portions "I, 002 a of the valve to pass between them. To the otherarm I of the bell crank is attached a link I2, connected at its other end to a foot pedal I3, whichmay be the throttle or accelerator pedal for the engine, although it is of course obvious that a separate pedal might be used if desired.

In such modified construction, resilient spring means "2 is interposed between the governor 

